The present invention relates to a fiber fabric and a composite material obtained by reinforcing a resin by the fiber fabric.
A load energy absorbing member constructing a bumper apparatus cushioning an impact at a collision of a vehicle absorbs the energy of an impact load applied to a bumper reinforcement constructing the bumper apparatus. In order to save weight of the bumper apparatus, there has been known a composite material in which the bumper reinforcement or the load energy absorbing member is formed by a fiber reinforced resin.
As the fiber for reinforcing the resin, for example, fabrics disclosed in the following publication can be employed.
A fabric disclosed in Japanese Laid-Open Patent Publication No. 63-303145 is structured such that the weft is diagonally woven in the warp. However, since the fabric is woven only by the warp and the weft, threads are bent and meander, and it is disadvantageous in view of improving the strength of the composite material.
In a fabric disclosed in Japanese Laid-Open Patent Publication No. 7-243147, the structure is made such that two perpendicular lines passing through the center of two warp threads or two weft threads adjacent to each other is connected the centerline of one of the warp and the weft, which intersect each other. An angle formed between the connecting line and a line which is in parallel to an arranging direction of the warp or the weft is set to be equal to or less than 1 degrees. That is, a crimp of the threads is small. However, in the case that the crimp exists although it is small, it is disadvantageous for improving the strength of the composite material.
In a fabric disclosed in Japanese Laid-Open Patent Publication No. 7-243149, an auxiliary thread group intersecting a flat reinforced fiber multi filament threads which do not have such a bending that a stress is concentrated is arranged in both sides of a sheet surface of a filament group in which the reinforced fiber multi filament threads are arranged in parallel to each other in one direction and in a sheet shape. Further, a warp direction auxiliary thread group and a weft direction auxiliary thread group keeping pace with the reinforced fiber multi filament thread form a woven texture and integrally hold the filament group. In this fabric, since the flat reinforced fiber multi filament threads are arranged in parallel to each other in one direction and in the sheet shape, the filament group with no crimp can be structured. Accordingly, the fabric is advantageous in view of improving a strength of the composite material and gives excellent moldability.
In order to increase the thickness of a composite material, it is preferable to overlap a plurality of fabrics. However, since the fabric in the Japanese Laid-Open Patent Publication No. 7-243149 is the fabric having a single layer sheet shape, the production efficiency in the case of producing the composite material having a large thickness is not good.